Ruler



FIG. 1 is a top left perspective view of a ruler showing my new design;

FIG. 2 is a left end elevational view thereof;

FIG. 3 is a front elevational view thereof, the rear being a mirror image thereto;

FIG. 4 is a right end elevational view thereof;

FIG. 5 is a top plan view thereof;

FIG. 6 is a bottom plan view thereof. 

The ornamental design for a ruler, substantially as shown and described. 